Cable guide structure

ABSTRACT

Abstract of Disclosure 
     A cable guide is provided for a movable body such as a chair having legs with casters.  The cable guide guides a cable attached to the movable member away from the casters during movement of the movable member and/or horizontal rotation of a portion of the movable member.

Background of Invention Field of the Invention

[0001] This invention concerns a cable guide structure which protectscables such as telephone cords, tubes or cables (hereafter called simply"cables") when they are connected to a revolving chair with casters onits legs in such a way that they trail freely on the floor. Morespecifically, when electricity is supplied from the exterior to arevolving office chair with casters on its legs to provide power for abuilt-in health appliance such as an electric massager, shoulder heateror shiatsu device, this cable guide structure protects the power supplycable from being run over by the casters or getting wound around thelegs of the chair. The scope of the invention is not limited to officechairs only; it could also be applied when a person seated in a chair isbeing monitored for pulse rate or other physiological data, or when acable is providing audio or video signals to a seated person.

Background of the Invention

[0002] An example of a revolving office chair with casters provided inthe prior art is shown in Figure 1 of USP 5,247,925 (Figure 7 herein).This revolving chair 500 moves freely about the floor with the rotationof casters 540. Its post 520 is able to rotate 360 degrees about itscenter in the horizontal plane. It is customary for a person seated insuch a revolving chair with casters to move about the floor while seatedin the chair. At such times, if the chair has a built-in electricalappliance to which a power supply cable 550 is connected, the cable maybe trapped under casters 540 (see Figure 8) so that the casters lock up,and the cable may be damaged. Or, as is shown in Figure 9, casters 540may run over the cable, so that it becomes entangled among legs 530.This will limit the mobility of the chair and may cause damage to thecable.

[0003] A prior art design to alleviate these problems, which wasproposed in USP 5,371,920, is shown in Figure 10. It provides acylindrical guard (cylindrical portion 137) around each caster (wheelassembly 119) so that the power supply cord cannot be run over. Anothersolution was offered in USP 4,025,099, shown in Figure 11. A panel(flipper plate 30) is provided on the front of each caster to keep thecable away from the wheels so that it cannot be run over. Panel 30 isattached by hinge pin 31 so that it hangs down under its own weight. Itsfront end 33, then, is normally in contact with the floor so that it canlift up the cable.

[0004] However, the prior art designs for office chairs do not addressthe problem illustrated in Figure 8, which occurs when several of thecasters are locked simultaneously by being trapped in a cable lying onthe floor. When one end of the cable is attached to the seat of thechair and the other is attached to a wall outlet, the cable's freedom ofmovement is limited. When the casters move, then, the cable can get hungup on them, which can result in the casters becoming locked. If peoplein an office frequently move their chairs around, this will happen againand again. When it does happen, the plug may be pulled out of the walloutlet, or the chair which is stuck may tilt on the fulcrum provided bythe casters and fall over.

[0005] Or, as is shown in Figure 9, the connection site 511 where thecable is attached to seat 510 may end up, when the seat rotates on post520, on the side of the chair opposite socket 522 and plug 551. Whenthis happens, the portion of electrical cord 550 which is on the floorcan easily become entangled among legs 530 so that it hinders the freemovement of casters 540. In the prior art solutions discussed above,then, cable connection site 511 lacks a stabilized directionality withrespect toward socket 552 and plug 551; thus the danger that the cablewill become entangled on casters 540 remains unaddressed.

Summary of Invention

[0006] This invention is developed in order to eliminate the problemsdiscussed above. The object of this invention is to provide a cableguide structure which would stabilize the direction of an electrical orother cable trailing onto the floor from a revolving office chair withcasters on its legs or some other revolving and movable body.

[0007] Another object of this invention is to provide a cable guidestructure which would make it difficult for the cable and casters tointerfere with each other regardless of the movement of the casters whenthe cable extends from a revolving, movable chair with a built-inelectrical appliance in such a way that it can move freely on the floor.

[0008] For this purpose, the cable guide structure according to thisinvention has a supporting arm which holds the electrical cablevirtually horizontal in the space above the legs of the chair so that itcannot be run over by the casters. This supporting arm is mounted to thepost of the chair in such a way that it can revolve around the post. Thearm supports the cable in the space above the legs and leads it out agiven distance from the post, where it is allowed to drop from the endof the arm to the floor. This distance is somewhat beyond the radius ofthe rotational path of the chair legs. Thus the cable which runs outfrom the chair is guided along the supporting arm until it is allowed todrop to the floor a sufficient distance beyond the casters. When thechair revolves or moves, the portion of the cable which is on the floorwill not be run over by the casters. In addition, this invention alsoprovides a caster sweeper unit for each caster to sweep away the portionof the cable which is on the floor. It thus offers two separate types ofcable guide structures to prevent the cable from being run over by thecasters

Brief Description of Drawings

[0009]Figure 1 illustrates a cable guide structure using a supportingarm according to the first preferred embodiment of this invention.

[0010]Figure 2 illustrates a cylindrical case to fix the supporting arm.

[0011]Figure 3 illustrates a cable guide structure using a supportingring according to the second preferred embodiment of this invention.

[0012]Figure 4 illustrates a cable guide structure using a conicalsupporting skirt according to the third preferred embodiment of thisinvention.

[0013] Figures 5A, 5B, and 5C illustrates a cable guide structure usinga caster sweeper according to the fourth preferred embodiment of thisinvention.

[0014]Figure 6 illustrates a cable guide structure using a caster beltaccording to the fifth preferred embodiment of this invention.

[0015]Figure 7 illustrates an office chair provided with a power cableaccording to a prior art.

[0016]Figure 8 illustrates a disadvantage of an office chair with apower cable according to a prior art.

[0017]Figure 9 illustrates another disadvantage of an office chair witha power cable according to a prior art.

[0018]Figure 10 illustrates another prior art structure.

[0019]Figure 11 illustrates another prior art structure.

Detailed Description

[0020] In this section we shall give a detailed explanation of severalpreferred embodiments of this invention, with reference to the appendeddrawings. Insofar as the dimensions, materials, shape, or relativepositions of the constituent parts described in these embodiments arenot specifically indicated, the scope of the invention is not limited tothe description given, which is meant merely as an illustration.

[0021]Figure 1 shows a cable guide structure 1 in accordance with afirst preferred embodiment of this invention. This structure includesboth a supporting arm 110 and caster sweepers 200 shown in Figures 5A,5B, 5C. Office chair 500, which has a built-in electrical massager,consists of seat 510, revolving post 520, which supports the seat, andlegs 530. Seat 510 can revolve in the horizontal plane on post 520. Legs530 all have casters 540 on their ends so that they can move freelyabout the floor.

[0022] Cable guide structure 1 supports electrical cable 550, whichsupplies power to the electrical massager in seat 510, in the spaceabove the legs of the chair, and leads it from seat 510 to a locationbeyond the path of rotation of legs 530. In this embodiment it includessupporting arm 110 and cylindrical case 120. Supporting arm 110 extendsoutward virtually horizontally from cylindrical case 120. It isnecessarily somewhat longer than legs 530. In other words, supportingarm 110 must be long enough so that the portion of the electrical cablewhich falls to the floor from the end of arm 110 cannot be run over anddamaged by casters 540 when the chair moves around the floor, and longenough so that the cable does not hinder the free movement of thecasters. The electrical cable 550 which originates in seat 510 is acurly cable. It is led to the site where supporting arm 110 is mounted(in the drawing, the left side of the arm 110) and supportedhorizontally as it is led through the space above legs 530. Thesupporting arm takes the cable beyond the range of the path of the legs,where it is allowed to drop to the floor.

[0023] As can be seen in Figure 2, cylindrical case 120 consists ofdiscrete cases 120-1, 120-2 and 120-3. These three cases surround andare concentric with rotary post 520. Each of the three cases can rotatefreely around the post and has a specific coefficient of friction withrespect to the other cases. Post 520 and the closest case, case 120-1,rotate freely with respect to each other at friction coefficient α₁.Case 120-1 rotates freely with the next case, 120-2, at frictioncoefficient α₂. Case 120-2 and the furthest case, 120-3, rotate freelywith each other at friction coefficient α₃. Thus the rotation moment n₁of case 120-1, the closest one to post 520, can be determined withrespect to the rotation moment n₀ of the post by the following.

[0024] n₁ = α₁ × n₀

[0025] Similarly, the rotation moment of cases 120-1 and 120-2 and thatof 120-2 and 120-3 can be obtained by the following.

[0026] n₂ = α₂ × n₁

[0027] n₃ = α₃ × n₂

[0028] Thus the friction coefficient of the furthest case, 120-3, withrespect to the rotation moment n₀ of post 520, is obtained by cumulatingthe three friction coefficients α_(1,) α₂ and α₃; so case 120-3 willbarely rotate with post 520. In other words, when seat 510, which isattached to post 520, rotates, supporting arm 110, which is attached tocase 120-3, will barely rotate. The electrical cable 550 which is guidedby the supporting arm will thus continue to lie in the same direction.

[0029] By providing a number of discrete cases, 120-1, 120-2, 120-3 wecreate a situation in which the coefficient of friction between each twocases is raised to a power of the coefficient of the previous two cases.Thus supporting arm 110, which is attached horizontally to the furthestcase, 120-3, will be independent of the rotation of post 520, which canthen rotate smoothly. The number of discrete cases needed is determinedby the cumulative coefficient of friction necessary to insure that thefurthest case, 120-3, will not be affected by the rotation of post 520and legs 530.

[0030] In the description given, the discrete cases are placed quiteclose to each other to achieve the appropriate coefficients of friction;however, the invention is not limited to this example only. Rodbearings, for example, could also be used between the cases.

[0031] With this configuration, supporting arm 110 rotates freely aboutpost 520. When post 520 rotates, then, electrical cable 550, which hangsdown at the end of supporting arm 110, will normally continue to lie onthe floor in the direction collinear with arm 110. The cable, that is,will not be pulled when seat 510 rotates. Supporting arm 110 is anappropriate height off the floor, and extends far enough from post 520,so that electrical cable 550 will not fall to the floor between two legs530. In other words, the supporting arm holds electrical cable 550 inthe space above legs 530 so that when the cable does go down to thefloor it cannot get tangled up in casters 540. Supporting arm 110 can beflexible so that when it is not being used it can be retracted andstored below the upper portion of the chair.

[0032]Figure 3 shows a second preferred embodiment. In place of thesupporting arm 110 in the first embodiment, this embodiment has asupporting ring 130. Ring 130 is fastened horizontally to the post inthe space above legs 530 by means of mounting hardware 131. The uppersurface 132 of ring 130 is fashioned of a smooth material and shapedsmoothly so that the electrical cable 550 which comes out of seat 510will move along this smooth surface when seat 510 rotates. The diameterR of ring 130 is greater than the diameter L of the floor area definedby legs 530. As a result, when electrical cable 550 falls to the floorfrom the edge of ring 130, it is further from the post than are thecasters 540 on the ends of legs 530. The portion of cable 550 which ison the floor cannot interfere with casters 540, and consequently casters540 cannot run over the portion of the cable on the floor. The chairillustrated in the Figure 3 embodiment may also employ caster sweepers200 shown in Figures 5(A), 5(B) and 5(C).

[0033]Figure 4 shows the third preferred embodiment of the invention.Here rotary post 520 and all of casters 540 are covered by skirt 140.Just as in the first embodiment, skirt 140 is mounted to post 520through a number of cylindrical cases 120 in such a way that it is freeto rotate. The lower edge of skirt 140 almost meets the floor, and itcovers the tops of casters 540 and their entire surfaces in such a waythat it keeps the portion of cable lying on the floor away from thecasters. The skirt could be made of a conical plastic cover or fashionedfrom a metal plate.

[0034] Because skirt 140 is conical in shape, when the electrical cable550 which comes out of seat 510 falls by its own weight onto the upperportion of the skirt, it will run along the surface of the cone down tothe floor. Since the bottom of the skirt almost touches the floor, theportion of the cable lying on the floor will be pushed away from thechair by the skirt even when the entire chair moves across the floor.This effectively prevents the cable from being run over by casters 540.

[0035] And because skirt 140 encloses the space above legs 530, itprevents cable 550 from falling to the floor between two adjacent legs530 and getting run over by casters 540.

[0036] Figures 5 (A), (B) and (C) show the configuration of a castersweeper 200, in a fourth preferred embodiment of the invention which canbe used on the casters of a chair having the cable guide structure ofFigures 1, 3 or even Figure 4, depending on how close skirt 140 comes tothe floor. The caster sweeper 200 can also be used with the casters of achair which does not have cable guide structure. Caster sweepers 200 aredevices to lift up the portion of the cable which is on the floor. Ascan be seen in Figure 5 (A), the caster sweeper has a tongue-shapedfront portion 201 which covers the front surface of caster 540. As canbe seen in Figure 5 (B), caster sweepers are mounted on both the frontand rear of each caster 540, which is fixed to the bottom of a leg 530.Front portions 201 extend almost to the floor and are bent in such a wayas to scoop up the portion of cable on the floor so that it remainsparallel to the floor. Front portions 201 should be fashioned from aflexible substance such as plastic so that even when casters 540 arepartially sunk into a soft carpet on the floor, portions 201 can come inclose contact with the top of the carpet. They might also be molded as asingle piece with caster covers 541. As can be seen in Figure 5 (C),front portions 201 may be fork-shaped.

[0037]Figure 6 shows the fifth preferred embodiment of this invention.In place of the caster sweepers of the third embodiment, this embodimenthas caster belt 210. Instead of discrete pairs of caster sweepers 200attached to individual casters 540 as in the third embodiment, casterbelt 210 is a single piece which covers all the casters 540 which areattached to the bottoms of the legs. It pushes away any cable lying onthe floor so that it will not be run over by casters 540. The top ofcaster belt 210 is fastened to legs 530. The bottom of the belt shouldbe fashioned from a flexible substance such as plastic so that even whencasters 540 are partially sunk into a soft carpet on the floor, the beltcan come in close contact with the top of the carpet.

[0038] This invention features a cable guide structure with a simpleconfiguration which guides an electrical cord or other cable beyond thereach of the legs of an office chair. The cord cannot interfere with therotation of the casters, so the chair can move smoothly around thefloor. If a supporting arm is used which is mounted to a cylindricalcase revolving independently of the post of the chair, the electricalcord will ordinarily remain in the same orientation and will not becomewound around the post.

[0039] The supporting arm 110, supporting ring 130 and skirt 120according to this invention can all be made cheaply from plastic. Theyare simple to mount and can be attached easily to any office chair.

[0040] Attaching caster sweepers 200 in front of the casters orinstalling a caster belt 210 will insure that any cable which happens toget close to a caster will be pushed away and will enable the officechair to be moved smoothly at all times.

[0041] Although the invention has been described above in connectionwith exemplary embodiments, it is apparent that many modifications canbe made without departing from the spirit or scope of the invention.Accordingly, the invention is not to be considered as limited by theforegoing description, but is only limited by the scope of the appendedclaims.

Claims
 1. A cable guide structure for a movable body which has legs,casters attached to said legs, and a horizontally rotatable portionsupported on said legs through a post, said guide structure comprising:a cable guide member for guiding a cable attached to said movable bodyin a manner which prevents said cable from interfering with said castersupon movement of said movable body or rotation of said horizontallyrotatable portion.
 2. A cable guide structure according to claim 1 ,comprising: a cylindrical case which can rotate freely around said postbut independently of the rotation of the post, and wherein said cableguide member comprises a supporting arm which is fixed to saidcylindrical case and extends horizontally from said case to support saidcable as it runs through a space over said legs.
 3. A cable guidestructure according to claim 2 , wherein said supporting arm, which isfixed to said cylindrical case, rotates freely around said post, and itsrotation is independent of the rotation of the post.
 4. A cable guidestructure according to claim 3 , wherein said cylindrical case comprisesa plurality of concentric cases which can rotate with respect to eachother, said supporting arm is fixed to said concentric case farthestfrom said post, and said supporting arm rotates freely and independentlyfrom the rotation of said post.
 5. A cable guide structure according toclaim 1 , wherein said cable guide member comprises a supporting ringhaving a diameter greater than a floor area defined by said legs, andwhich is installed horizontally between said legs and the horizontallyrotating portion, such that said cable, when hanging down from saidmovable body, is able to slide on said supporting ring which guides thecable to a location on the floor further from the post than the legs. 6.A cable guide structure according to claim 1 , comprising: a cylindricalcase which can rotate freely around a post but independently of therotation of the post, and wherein said cable guide member comprises aconical supporting skirt which is concentric with said cylindrical caseand extends from said cylindrical case outwardly and downwardly toward afloor whereby a cable hanging down from said movable body slides downalong said skirt and is guided to the floor at a location farther fromthe post than said legs.
 7. A cable guide structure according to claim 1, further comprising a caster sweeper installed on the front of each ofthe casters so that a cable on a floor will not interfere with saidcasters.
 8. A cable guide structure according to claim 1 , furthercomprising a caster belt which completely covers the forward rotatingsurfaces of the casters so that a cable on a floor will not interferewith said casters.
 9. A cable guide structure according to claim 1 ,wherein said movable body provided with said cable guide structure is anoffice chair equipped with an electric appliance.
 10. A cable guidestructure according to claim 2 , further comprising a caster sweeperinstalled on the front of each of the casters so that a cable on a floorwill not interfere with said casters.
 11. A cable guide structureaccording to claim 5 , further comprising a caster sweeper installed onthe front of each of the casters so that a cable on a floor will notinterfere with said casters.
 12. A cable guide structure according toclaim 6 , further comprising a caster sweeper installed on the front ofeach of the casters so that a cable on a floor will not interfere withsaid casters.
 13. A cable guide structure according to claim 2 , furthercomprising a caster belt which completely covers the forward rotatingsurfaces of the casters so that a cable on a floor will not interferewith said casters.
 14. A cable guide structure according to claim 5 ,further comprising a caster belt which completely covers the forwardrotating surfaces of the casters so that a cable on a floor will notinterfere with said casters.
 15. A cable guide structure according toclaim 6 , further comprising a caster belt which completely covers theforward rotating surfaces of the casters so that a cable on a floor willnot interfere with said casters.
 16. An office chair provided with cableguide structure for a movable chair body which has legs, castersattached to said legs, and a horizontally rotatable seat portionsupported on said legs through a post, said guide structure comprising:a cable guide member for guiding a cable attached to said chair body ina manner which prevents said cable from interfering with said castersupon movement of said chair body or rotation of said horizontallyrotable seat portion.
 17. An office chair according to claim 16 ,wherein said cable guide structure comprises: a cylindrical case whichcan rotate freely around a post but independently of the rotation of thepost, wherein said cable guide member comprises a conical supportingskirt which is concentric with said cylindrical case and extends fromsaid cylindrical case outwardly and downwardly toward a floor whereby acable hanging down from said movable chair body slides down along saidskirt and is guided to the floor at a location farther from the postthan said legs.
 18. An office chair according to claim 17 , wherein saidcylindrical case comprises a plurality of concentric cases which canrotate with respect to each other, said supporting arm being fixed tosaid concentric case farthest from said post, and said supporting armrotating freely and independently from the rotation of said post.